HYBRID-TYPE WORK MACHINE

An assist generator motor (12) is driven by an engine (8) to generate power or assists in a drive of the engine (8) by supply of power from an electricity storage device (25). A revolving electric motor (29) is driven by power supplied from the electricity storage device (25) or supplies regeneration power generated by a regeneration operation to the electricity storage device (25). The assist generator motor (12) is controlled by a first inverter (46). The revolving electric motor (29) is controlled by a second inverter (55). The first inverter (46) and the second inverter (55) are mounted on a support bracket (37) elastically supported on a revolving frame (5) in a position different from a position where the electricity storage device (25) is mounted.